<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar @click-left="onClickLeft" class="page-nav-bar" left-arrow title="黑马头条"></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap" ref="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading" class="loading-wrap">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{article.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image class="avatar" slot="icon" round fit="cover" :src="article.aut_photo" />
          <div slot="title" class="user-name">{{article.aut_name}}</div>
          <div slot="label" class="publish-date">{{article.pubdate|relativeTime}}</div>
          <!-- 关注按钮
          :isfollow="article.is_followed"
            @update-follow="article.is_followed=$event"
          -->
          <follow-user
            class="follow-btn"
            :articleid="article.aut_id"
            v-model="article.is_followed"
          />
          <!-- 模板中的$event是事件参数 -->
          <!-- 关注按钮/ -->
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          ref="article-content"
          v-html="article.content"
        >文章内容</div>
        <van-divider>正文结束</van-divider>

        <!-- 评论区域 -->
        <div ref="commentList">
          <comment-list
            :list="commentList"
            :articleDetail="article"
            @total_count="totalCommentCount"
          />
        </div>

        <!-- /评论区域 -->

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button
            @click="popup_show=true"
            class="comment-btn"
            type="default"
            round
            size="small"
          >写评论</van-button>
          <van-icon @click="Movetocomment" name="comment-o" :badge="totalComment" color="#777" />
          <collect-article :article-id="articleID" v-model="article.is_collected" class="btn-item"></collect-article>
          <like-article :article-id="articleID" v-model="article.attitude"></like-article>
          <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->
        <van-popup v-model="popup_show" position="bottom">
          <comment-post @post-success="addComment" :articleID="articleID" />
        </van-popup>
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div v-else-if="errStatus === 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button @click="loadArticle" class="retry-btn">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>
  </div>
</template>

<script>
// 这里可以导入其他文件（比如：组件，工具js，第三方插件js，json文件，图片文件等等）
// 例如：import 《组件名称》 from '《组件路径》';
import { ImagePreview } from 'vant'

import { getArticlebyIDAPI } from '@/api/article'
import CollectArticle from '@/components/collect-article'
import FollowUser from '@/components/follow-user'
import LikeArticle from '@/components/like-article'
import CommentList from './components/comment-list'
import CommentPost from './components/comment-post.vue'
export default {
  name: 'ArticleDetail',
  // import引入的组件需要注入到对象中才能使用
  components: { FollowUser, CollectArticle, LikeArticle, CommentList, CommentPost },
  props: {
    articleID: {
      type: [Number, String, Object],
      require: true
    }

  },
  data () {
    // 这里存放数据
    return {
      article: {}, // 文章详情
      loading: true, // 加载状态
      errStatus: 0, // 失败的状态码
      totalComment: 0, // 评论总数
      popup_show: false, // 控制弹出层
      commentList: []// 評論列表
    }
  },
  // 计算属性 类似于data概念
  computed: {},
  // 监控data中的数据变化
  watch: {},
  // 方法集合

  methods: {
    // 发布评论后
    addComment (data) {
      // 关闭弹出
      this.popup_show = false

      this.commentList.unshift(data.data.new_obj)
    },

    totalCommentCount (e) { this.totalComment = e },
    // 回退功能
    onClickLeft () {
      this.$router.back()
    },
    // 图片预览
    onImageClick () {
      const imgs = this.$refs['article-content'].querySelectorAll('img')
      const images = []
      imgs.forEach((img, index) => {
        images.push(img.src)
        img.onclick = () => {
          ImagePreview({
            // 预览的图片地址数组
            images,
            // 起始位置，从0开始
            startPosition: index

          })
        }
      })
    },
    async loadArticle () {
      this.loading = true
      try {
        const { data } = await getArticlebyIDAPI(this.articleID)
        this.article = data.data
        setTimeout(() => {
          this.onImageClick()
        }, 0)
      } catch (error) {
        if (error.response && error.response.status === 404) {
          this.errStatus = 404
        }
        this.$toast('获取失败', error)
      }
      // 无论成功失败都关闭loading
      this.loading = false
    },
    // 点击评论图标移动到评论区域
    Movetocomment () {
      const main = this.$refs['main-wrap']
      const offset = this.$refs.commentList.offsetTop
      main.scrollTop = offset
    }
  },
  // 生命周期 - 创建完成（可以访问当前this实例）
  created () {
    this.loadArticle()
  },
  // 生命周期 - 挂载完成（可以访问DOM元素）
  mounted () {

  },
  beforeCreate () { }, // 生命周期 - 创建之前
  beforeMount () { }, // 生命周期 - 挂载之前
  beforeUpdate () { }, // 生命周期 - 更新之前
  updated () { }, // 生命周期 - 更新之后
  beforeDestroy () { }, // 生命周期 - 销毁之前
  destroyed () { }, // 生命周期 - 销毁完成
  activated () { } // 如果页面有keep-alive缓存功能，这个函数会触发
}
</script>
<style scoped lang='less'>
@import './github-markdown.css';
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    /deep/.van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    /deep/.van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
